Refrigerant dryer service valve

ABSTRACT

A generally cylindrical centrally bored housing is connected, at one end, with the converging end wall of an evacuated refrigerant dryer. A valve equipped tubular core, having a length slightly greater than the length of the housing, is coaxially received therein with a line piercing tip formed on the core end contacting the housing surrounded dryer surface. A cap, threadedly engaged with the other end of the housing, forces the line piercing tip through the dryer wall for communication with the interior of the dryer.

United States Patent. 11 1 Mullins Nov. 4, 1975 REFRIGERANT DRYERSERVICE VALVE Primary Examiner-l-Ienry T. Klinksiek [76] Inventor: Johnw. Mullins, P.O. Box 20524, Ammey Agent firm-Robe" Rhea Oklahoma City,Okla. 73120 22 Filed: Aug. 12, 1974 [57] ABSTRACT A generallycylindrical centrally bored housing is con- [21] Appl' 496790 nected, atone encl, with the converging end wall of an evacuated refrigerantdryer. A valve equipped tubular 52 U.S. c1. 62/292; 137/318 e having alength g y greater than the length of 51 Im. cl. F25B 45/00 the housing,i eeaxially received therein with a line 58 Field of Search 137/317,318; 62/292 p g p formed en the core end contacting the housingsurrounded dryer surface. A cap, threadedly [56] Ref ren Cit d engagedwith the other end of the housing, forces the UNITED STATES PATENTS linepiercing 'tip through the dryer wall for communi- 3 448 758 6/1969Mullins 137/318 cation with the interior of the dryer.

.1 Claim, 4 Drawing Figures U.S. Patent Nov. 4, 1975 3,916,642

REFRIGERANT DRYER SERVICE VALVE CROSS REFERENCE TO RELATED APPLICATION IBACKGROUND OF THE INVENTION 1. Field ofthe Invention Thepresentinvention relates to sealed refrigerant systems and moreparticularly to a service valve for connection with a refrigerantdryer.

As is well known in the art, it is necessary, to maintain a sealedrefrigerant system free of moisture. This is accomplished by a tubularunit containing a desiccant which is interposed in a refrigerant line.However, the capacity of the desiccant is sometimes exceeded and itbecomes necessary to check the dryer to determine if it containsmoisture and to evacuate the refrigerant system and recharge it withrefrigerant gas and possibly replace the dryer. Further, it is importantthat the dryer-remainsealed'and free of moisture throughout-its shelflife so that when interposed in a refrigerant line thedryer willbecapable of absorbing moisture in the refrigerant system. This isaccomplished in the present invention by the access valve connected withthe dryer remaining dormant until operated by the serviceman to. piercethe wall of the dryer to communicate with the interior thereof.

2. Description of the Prior Art The most pertinent prior art is my US.Pat. No. 3,448,758, which discloses a centrallyv bored housing securedto a refrigerant line by a substantially C-shaped member partiallysurrounding the line and entering an annular groove in the housing. Thehousing bore coaxially receives a gas passing valve equipped tubularcore having a line piercing tip at one end which is sealed within thehousing during the line piercing action by a cap threadedlyeng aging thehousing'end portion opposite-the line and forcing the housing wall overthe adjacent edge of the tubular core. The tubular core and housingboreare provided with cooperating transverse shoulders which areintendedto form a fluid tight seal between the periphery of the core andhousing bore, however, this seal is difficult to attain where theshoulders are perpendicular to the axes of .the housing and core. Thehousing and tubular core of this invention are provided withcooperatingtapered seats which form a gas tight seal in a wedgin'gactionof the core seat against the housing seat when the core is forcedthrough the wall of the dryer.

A further feature of this invention is that the tubular 'core remainsinactive until actuated by a service man to pierce the refrigerant wall,therefore, insuring that a refrigerant dryer remains dry throughout itsshelf life and in trouble-free refrigerating system operating life untilsuch time communication with the bore of the dryer or refrigerant systemlines is necessary.

SUMMARY OF THE INVENTION A generally cylindrical centrally boredhousing, having wrench flats intermediate its ends, is externallythreaded adjacent one end portion and diametrically reduced at its otherend portion. The housing is counterbored from its threaded end to form atapered annular shoulder intermediate its ends and define a thin wallportion outwardly of the threads. A generally cylindrical centrallybored core is provided with an annulartapered shoulderintermediate itsends and a line piercing tip projecting coaxially beyond a smaller endportion. The overall length of the core is slightly greater than theaxial length of the housing a distance at least slightly greater thanthe thickness of the dryer wall. The end of the core opposite its'linepiercing tip is internally threaded for receiving an air valve coreopening and closing the bore of the core. The core is normally axiallyreceived by the housing andmaintained'therein by a cap engaging thehousing threads with the core 'pierc-"' ing tip in contact with thedryer wall. When communication with the dryer is required the cap isfurther threade'dly engaged with the housing thus forcing the piercingtip through the dryer wall and forcing a portion of the housing wall inoverlapping sealing relation with respect to the end of the coreopposite itspiercing tip in response to the core piercing the dryer walland simultaneously seating on the housing seat.

The principal object of this invention is to provide a service valvecontaining housing which is attached to a refrigerant dryer arcuate endwall at the time of manufacture to provide communication with the boreof the dryer at a selected time. E

BRIEF DESCRIPTION OF THE DRAWINGS DESCRIPTION OF THE PREFERREDEMBODIMENT Like characters of reference designate like parts in thosefigures of the drawings in which they occur.

In the drawings: The reference numeral 10 indicates the conventionalrefrigerant dryer comprising a cylindrical body or wall portion 12having its opposing end portions arcuately curved inwardly in convergingrelation and terminating in diametrically reduced end portions 14coaxially connected with tubes 16 having their opposite ends closed,

as by soldering 18. The dryer contains a desiccant, not shown, and thedryer is evacuated before sealing the tubes 16. One of the dryers 10 isinterposed in a refrigerant conductor line of a closed refrigerantsystem at the time of manufacture. When it is necessary to replace thedryer in a refrigerant system a new dryer, as just described, is placedtherein in the well known manner.

The reference numeral 20 indicates the dryer service valve, as a whole,which comprises a rigid, preferably brass, valve housing 22 havingwrench flats 24 intermediate its ends and external threads 26, at oneend portion. The other end portion of the housing is diametricallyreduced, as at 28, and abuts and is secured to the wall 12 of the dryer,as by brazing 30. The housing is centrally bored, as at 32, andcounterbored, as at 34, from its threaded end to form a tapered shoulder36 intermediate its ends. The end portion of the housing outwardly ofthe threads is diametrically reduced to form a free end thin wallportion 38 for the purposes presentlyexplained.

l A generally cylindrical core 40, preferably formed of steel, andlongitudinally slightly greater than the spacing between the ends of thehousing by a distance at least as great as the thickness of therefrigerant wall 12 is coaxially received by the housing 22. The core 40is characterized by a larger end portion 42 slidably received by thecounterbore 34 and a smaller end portion 44 slidably received by thehousing bore 32 and defining a tapered shoulder 46 facing toward thehousing shoulder 36. The reduced end portion of the core 40 is providedwith a-diametrically reduced tapered end portion forming-a wall piercingtip 48 projecting beyond an annular shoulder 49 and having a beveled endsurface 50 for piercing the dryer wall 12, as hereinafter explained.

The core 40 is bored and counterbored from its larger end in stepdiameter fashion to define a valve seat 52 and is internally threaded,as at 54, for receiving a conventional air valve 56 for opening andclosing the bore of the core 40. The wall of the core 40, adjacent itsthreaded end, is diametrically reduced to form an annular shoulder 58for the purposes presently explained. I

A dust cap 60 is internally threaded for engaging the housing threads 26and is provided with a tapered wall surface 62 at the inner limit of itsthreads converging toward the axis of its closed end 64.

OPERATION In operation the service valve is connected with the dryerbody wall 12, as described hereinabove, at the time of manufacture andevacuation of the dryer 10. The core 40 is manually positioned withinthe valve housing 22 and the cap 60 hand tightened on the housingthreads 26. THe valve components remain in the position illustrated inFIG. 2 until communication with the bore of the dryer is needed. Theserviceman then tightens the cap 60 by using a wrench on the cap and aback-up wrench on the housing shoulders 24 which forces the linepiercing tip 48 through the dryer body wall 12 while simultaneously thetapered surface 62,0f the cap forces the body thin wall portion 38inwardly against and in overlapping relation with respect to the coreshoulder 58 while the core shoulder 46, being impinged against thehousing shoulder 36, forms a seal therewith and a positive stop againstaxial movement of the core 40 into the housing while pressure is beingapplied thereto by the cap in sealing the housing thin wall 38 with thecore. Thereafter the cap 60 may be removed and communication obtainedwith the dryer core through the air valve 56.

Obviously the invention is susceptible to changes or alterations withoutdefeating its practicability, therefore, I do not wish to be confined tothe preferred embodiment shown in the drawings and described herein.

I claim:,

1. A service valve in combination with a refrigerating system dryer,said dryer having arcuate converging end wall surfaces, the improvementcomprising:

a generally cylindrical centally bored housing having wrench flatsintermediate its ends and a diametrically reduced periphery forming arelatively thin wall having a free end surface at one end portion, saidhousing being counterbored from its thin wall end to form an annulartapered shoulder intermediate its ends facing toward said thin wallportion,

said housing having external threads extending between said wrench flatsand said thin wall portion,

the other end portion of said housing being diametrically reduced andconnected in end abutting relation with one arcuate end wall of saiddryer by brazing; a tubular core, having a length slightly greater thanthe spacing between the free end surface of said housing thin wallportion and said other end of said housing, cooperatively receivedcoaxially by the bore of said housing, said core having a diametricallyreduced tapered end portion converging toward the tubular member wall tobe pierced,

said tapered end portion terminating in a beveled end surface forming awall piercing tip,

said core having an external beveled surface intermediate its endsforming an annular shoulder facing toward the wall piercing tip,

said core having a diametrically reduced peripheral portion adjacent itsend opposite said line piercing tip forming an annular shoulder adjacentthe housing thin wall portion, said core having internal threads at itsend portion opposite said wall piercing tip and having a seat formed onits inner wall surface at the inner limit of the threads;

an air valve sealing with the seat in said core; and,

a cap engagingthe threads on said housing and axially moving said coretoward said tubular member wall in a wall piercing action whilesimultaneously seating and sealing said core within said housing.

1. A service valve in combination with a refrigerating system dryer,said dryer having arcuate converging end wall surfaces, the improvementcomprising: a generally cylindrical centally bored housing having wrenchflats intermediate its ends and a diametrically reduced peripheryforming a relatively thin wall having a free end surface at one endportion, said housing being counterbored from its thin wall end to forman annular tapered shoulder intermediate its ends facing toward saidthin wall portion, said housing having external threads extendingbetween said wrench flats and said thin wall portion, the other endportion of said housing being diametrically reduced and connected in endabutting relation with one arcuate end wall of said dryer by brazing; atubular core, having a length slightly greater than the spacing betweenthe free end surface of said housing thin wall portion and said otherend of said housing, cooperatively received coaxially by the bore ofsaid housing, said core having a diametrically reduced tapered endportion converging toward the tubular member wall to be pierced, saidtapered end portion terminating in a beveled end surface forming a wallpiercing tip, said core having an external beveled surface intermediateits ends forming an annular shoulder facing toward the wall piercingtip, said core having a diametrically reduced peripheral portionadjacent its end opposite said line piercing tip forming an annularshoulder adjacent the housing thin wall portion, said core havinginternal threads at its end portion opposite said wall piercing tip andhaving a seat formed on its inner Wall surface at the inner limit of thethreads; an air valve sealing with the seat in said core; and, a capengaging the threads on said housing and axially moving said core towardsaid tubular member wall in a wall piercing action while simultaneouslyseating and sealing said core within said housing.